1. Field of the Invention
The present invention relates to a technique of controlling a game.
2. Description of the Related Art
A game system is known that performs a battle game in which a player uses a game medium such as a card (character card) or the like (see Patent Document 1, for example).
Winning or losing in the battle game is determined based on a parameter such as an attack power, a defense power or the like set for each card.
Thus, it is difficult for the player who only has weak cards to easily win the battle game and thus, there has been a problem in that such a player cannot feel interested in the game.
Further, even where the player has strong cards in addition to the weak cards, there has been a problem in that there is no way to use the weak cards in the game.
Meanwhile, in such kinds of games, an event may be held in which players form a team to beat an enemy by cooperating with each other in a team battle.
However, as a contribution to a team weighs in the team battle, there has been a problem in that a player who only has weak cards cannot contribute to the team and cannot feel interested in the game.
Further, during an event period, there is a case that a predetermined card, among cards possessed by the players, is set to have an attack power value that is a few times of an attack power value of the card at a normal state, as a special attack card. There are some kinds of special attack cards, and some of them are set to have attack power values that are 2 to 15 times that of the attack power values of the cards at normal, respectively. Thus, for the player who has a special attack card whose attack power value is 15 times of normal, a special attack card whose power value is twice that of normal is seldom used, and as the card returns to a normal card after the event period ends, there was no way to use the card.